Presser foot mechanism



Oct. 4, 1932. BOWMAN -PRESSER FOOT MECHANISM Filed Dec. 22, 1950Patented Oct. 4, 1932 lUNlTED STATS LOUIS e. BOWMAN, orsr. LOUIS,MISSOURI, ASSIGN'OR T0 LEWIS INVISIBLE s'ri'ron MACHINE COMPANY, or s'r.LonIs, MISSOURI, A conrone'rron or MAINE V v although my riznssnn r001MECHANISM Application filed December 22, 1930. Serial No. 504,134.

This invention relates to new and useful improvements in presser footmechanisms for high speed sewing machines generally, invention isparticularly adapted for double lap seaming operations wherein thefolded-edge portions are joined by two lines of straight-away stitches.

One of the principal objects of my invention is to provide a presserfoot which will chain off properlybetween garments without sacrificingthe pressure necessary to feed the garment through the machine at highspeed. i V

With this and other objects in view which will more fully appear, thenature of the invention will be more clearly understood by following thedescription, the appended claims, and the several Views illustrated inthe accompanying drawing. In the accompany1ng'draw1ng:

Figure 1 is a fragmentary side elevation of a feed-olf-the-arm type ofsewing machine showing the application or my invention,

Figure 2 is a horizontal sectional view of the presser foot showing itsrelation to the double lap seam of the garment,

Figure 3 1s a side elevation of the foot, Figure 4 1s a vertlcallongitudinal sectional view of the foot showing the auxilioverhangingarm. Supported in the over hanging arm is a vertically reciprocatoryneedle bar 8 carrying needles 9, 9 which cooperate with a complementalstitch forming mechanism (not shown) located in the work arm for makingtwo lines of straight-away stitches. Also mounted in the overhanging armis a presser bar-l0 which ispressed downwardly by a spring 11.

Mounted on the lower end of the bar is a main presser foot A and anauxiliary presser foot B which cooperate with a feed dog 12 to feed thebody fabrics C and D past the stitch forming mechanism.

The auxiliary foot B is pivoted and is bodily movable verticallyindependently of the main foot A for accommodating a double lap seamformed in the body fabrics, and

for engaging the chains between articles in a manner to insure thechains being properly'formed and fed rearwardly, especially when themachine is being operated at high speed. V

The main presser foot A comprises a flat body portion 13 whichterminates at its front end in an upwardly extending toe 14 having adownwardly extending groove 15 in its front face. a'lhe body portion 13is provided with a centrally located opening 16 which eX- tendsforwardly from the rear edge 17 of the body portion and merges with thegroove 15 at the base of the toe 14, the width of the openingcorresponding to the width of the groove 15 and being located inalinement therewith. Rigid with the rear part of the body portion arespaced upstanding cars '18, 18 which are pivotally connected by pivotscrews 19, 19 to the arms20, 20 which are rigidly connected to a clamp21 fixedly secured to the lower end of the main presser bar 10. i

The auxiliary presser foot B is disposed within the opening 16 andcorresponds in area thereto. This auxiliary presser foot B includes abody portion 22 which is provided with needle openings 23, 23. Rigidlyconnected to the rear part of the body portion 22 is a pair ofupstanding ears 24, 24: to which the forward end of an arm 25 ispivotally connected by a pivot pin 26. The rear end of the" arm 25 isformed into afclamp 27 which is fixedly secured to the lower end portionof an auxiliary presser bar 28 which is mounted within a bore 29 formedin the lower end of the presser bar 10 and is capable of longitudinalmovements relative thereto. The longitudinal'movements of theauxiliaryfpresser bar 28 relative to the main presser bar 10 are limitedby a cross pin 30 which projects outwardly through longitudinal openings31, 31 formed in the main presser bar 10 and communicating with the bore29 thereof. Secured to the main presser bar 10 above the bore29isacollar32and disposed around the main presser bar 10 between thecollar and the cross pin 30 is a coil spring 33 which yieldably urgesthe auxiliary presser bar 28 downwardly together with the auxiliary footB. It will be noted that the arm 25 projectsforwar-dly between the arms20, 20 to which the main presser foot A is pivotally connected.

This machine is especially adapted for double lap seaming operations andthe adj acent edges of the body fabrics C and D are turned into thefolder F whereby four thicknesses of material are fed into the groove'l5of the main presser foot A and thence rearwardly underthe auxiliarypresser foot B where they are united by two lines of straightawaystitches. When the body fabrics are in said position under the presserfeet and B, the main foot A bears on the respective body fabrics onopposite sides of the same and the auxiliary foot B is raised againstthe tension of the spring 33 by the threethicknesses of fabric. Thespring 33 is weaker than the spring 11 and consequently the main foot1'1 is yieldably held against upward movement while permitting theauxiliary afoot Bto be raised. hen the lap seam is disposed under theauxiliary foot B, the latter is raised until the clamp 27 engages thelower end of the main presser bar 10 and in this position of the partsequal pressure is exerted on both presser feet. As the garments are fedrearwardly from the presser feet the auxiliary presser foot B will belowered by the spring 33 onto the chain of stitches being formed and byreason of the spring 33 being lighter than the spring 11, these stitcheswill be properly formed. When the next garment is inserted under the toe14 of the main foot A, the lap seam will raise the front end of theauxilary foot B and thereby cause the heel of said auxiliary foot tomaintain its engagement with the connected chain and continue tocooperate therewith to properly formthe chain until said garment reachesthe needles.

The rear end 22a of the auxiliary foot B terminates under the pivot 26of the foot immediately in rear of the right hand needle hole 23, and inadvance of the rear end 17 of the main foot AQ This insures the heel ofthe auxiliary foot to quickly step down onto the chain or chains, and inorder to force the front end of this auxiliary foot to quickly step downand thereby engage and hold the chain or chains on the throat plate toprevent the loopers from entering the thread loops for the second time,'I have attached a spring 226 to the arm 25 in a manner to cause thefront end of the spring to bear downwardly against the auxiliary foot ata point inadvance of the pivot thereof.

cially with a high speed double lock stitch 'cle of operation tend tocut the threads and V iliary section locatedsrin the opening, the

It is a well known fact to those skilled in the art of high speed sewingmachines that the pressure of the main presser foot must be increased inproportion to the speed of the machine in order for the usuall-motionfeed dog to properly cooperate with the foot and feed the fabricatuniform stitch length distances. It is also a well known fact thatwhen chaining, off between garments, espemachine, too much pressure onthe presser foot will result in a failure to chain ofi due to the factthat the feed dog teeth which clamp the chain against the foot duringevery cythereby prevent the chain from being formed because the chainwill not be fed astitch length distance and thereby open the looperthread triangle for the reception of the needle thread loop. Myinvention is particularly adapted for double lap seaming operations andfor chaining off between garments. The auxiliary pressure foot sectionis bodily movable vertically independently of the main presser footsection and is normally held against upward movement by the spring 33which is lighter than the main presser foot spring 11.

By reason of the auxiliary foot section being movable verticallyindependently of the main foot section, the double lap fell of the seammaybe readily accommodated by the presser foot regardless of thethickness of the material being seamed. The auxiliary presser footsection is pivotally mounted on the auxiliary presser-foot bar and therear end of said auxiliary section is located directly below the pivotof said section and in front of the rear end of the main foot section.Consequently when the last end of a seam passes rearwardly. beyond theauxiliary section, the rear end of said section will engage the chainprior to the garment leaving the main section, and when anew garment isinserted under the front end of the presser foot, the auxiliary sectionwill swing about its pivot and the rear end of said auxiliary sectionwill engage the chain and remain in engagement therewith until thegarment substantially reaches said chain. .c

Thus it will be seen that I have provided a presser foot mechanism whichwill function to chain oif between garments without sacrificing thepressure necessary to feed the garments through the machine at highspeed. It is of course to be understood-that the details of structureand arrangements 'of parts may be variously changed and modified withoutdeparting fromthe spirit and scope of my invention. V

I claim y 1. In a presser foot mechanism for sewing machines, thecombination with a main presser bar, of a presser foot including a mainsection provided with an opening and an aux- C ll lower end of the mainpresser bar being provided with an upwardly extending bore and withdiametrically opposite openings communicating with the bore, a forwardlyextending arm clamped to the bar, a pivotal connection between the armand the main foot section, an auxiliary presser bar slidably mounted inthe bore of the main presser bar and having its lower end projectingtherebelow, a forwardly extending arm clamped to the projecting end ofthe auxiliary presser bar below the main presser bar, a pivotalconmotion between the last mentioned arm and the auxiliary foot section,the pivotal'connections between the arms and the foot sections beingnormally in axial alinement, a collar fixed to the main presser bar, apin fixed to the auxiliary presser bar and projecting outwardly throughthe openings in the main bar, and a spring weaker than the main presserbar spring surrounding the main bar between the collar and the pins.

2. In a presser foot mechanism for sewing machines, the combination witha main presser bar, of a presser foot including a main section providedwith an opening and an auxiliary section located in the opening, thelowor end of the main presser bar being provided with an upwardlyextending bore and with diametricall o ositeo 8I1l11 S communicat ingwith the bore, a forwarding extending arm clamped to the bar and havingforked arms at its front end, pivotal connectlons between the forkedarms and the main foot section, an auxiliary presser bar slidablymounted in the bore of the main presser bar and having its lower endprojecting therebelow, a forwardly extending arm clamped to theprojecting end of the auxiliary presser bar below the main presser bar,a pivotal connection between the last mentioned arm and the auxiliaryfoot section, the pivotal connections between the arms and the footsections being normally in axial alinement, a collar fixed to the mainpresser bar, a pin fixed to the auxiliary presser bar and projectingoutwardly through the open ngs in the main bar, and a spring weaker thanthe main presser bar spring surrounding the main bar between the collarand the pins.

3. In a presser foot mechanism for sewing machines, the combination witha spring presser bar, of a presser foot including a main sectionconnected to said bar and having an opening centrally formed therein, anauxiliary foot section located in said opening, said auxiliary footsection being formed with needle openings, and a connection between thepresser bar and the auxiliary foot section including an arm slidablymounted on the presser bar and connected to the auxiliary foot sectionwhereby the latter may move bodily upward and independently of the mainfoot section, and a spring for urging said auxiliary foot sectiondownwardly.

4. In a presser foot mechanism for sewing machines, the combination witha spring pressed presser bar, of a presser foot including a main sectionconnected to said bar and having an opening centrally formed therein, anauxiliary foot section located in said opening, said auxiliary foot.section being formed with needle openings, and a connection between thepresser bar and the auxiliary foot section including an arm slidablymounted on the presser bar and connected to the auxiliary foot sectionwhereby the latter may move bodily, upward and independently of the mainfoot section, a spring for urging said auxiliary foot sectiondownwardly, a stop on the presser bar for limiting the upward bodilymovement of the auxiliary foot sec tion, and a spring interposed betweenthe presser bar and the auxiliary foot section for yieldably retainingthe latter against upward bodily movement.

5,. In a presser foot mechanism for sewing machines, the combinationwith a spring pressed presser bar, of a presser foot including a mainsection connected to said bar and having an opening centrally formedtherein, an auxiliary foot section located in said opening, saidauxiliary foot section being formed with needle openings, and aconnection between the presser bar and the auxiliary foot sectionincluding an arm slidably mounted on the presser bar and connected tothe auxiliary foot section whereby the latter may move bodily upward andindependently of the main foot section, and a spring for urging saidauxiliary foot section downwardly, the arm and the auxiliary footsection being connected by a pivot located in front of the rear end ofthe, main section and directly above thesrear end of the auxiliarysection.

6. In a presser foot mechanism for sewing machines, the combination witha spring pressed presser bar, of a presser foot including a main sectionconnected to said bar and having an opening centrally formed therein, anauxiliary foot section located in said opening, said auxiliary footsection being formed with needle openings, anda connection between thepresser bar and the auxiliary foot section including an arm slidablymounted on the presser bar and connected to the auxiliary foot sectionwhereby the latter may move bodily upward and independently of the mainfoot section, a spring for urging said auxiliary foot sectiondownwardly, the arm and the auxiliary foot section being connected by apivot located in front of the rear end of the main section and directlyabove the rear end of the auxiliary section, a stop on the presser barfor limiting the upward bodily movement of the auxiliary foot section,and a spring interposed between the presser bar and the auxiliary footsection for yieldably retaining the latter against upward bodilymovement.

Ila.

7. In a presser foot mechanism for sewing machines, the combination witha main presser bar, of a spring for urging the main presser bardownwardly, a presser foot including a main section provided with anopening and an auxiliary section located in the opening, the lower endof the main presserbar being provided with an upwardly extending bore, aforwardly extending arm clamped to the bar and connected to the mainfoot section, an auxiliary presser bar slidably mounted in the bore ofthe main presser bar and having its lower end projecting therebelow, aforwardly extending arm clamped to the projecting end of the auxiliarypresser bar below the main presser bar, a connection between the lastmentioned arm and the auxiliary foot section, and a spring interposedbetween the presser bars for yieldably retaining the auxiliary footsection against upward bodily movement. 8. In a presser foot mechanismfor sewing machines, the combination with a. main presser bar, of aspring urging the main presser bar downwardly, a. presser foot includinga main section provided with an opening and an auxiliary section locatedin the opening, the lower end of the main presser bar being providedwith an upwardly extending bore, a so forwardly extending arm clamped tothe bar and connected to the main foot section, an auxiliary presser barslidably mounted in the bore of the main presser bar andhaving its lowerend projecting therebelow, a forward ly extending arm clamped to theprojecting end of the auxiliary presser bar below the main presser bar,a pivotal connection between the last'mentioned arm and the auxiliaryfoot section, the pivot being located 40 in front of the rear end of themain foot section and directly above the rear end of the auxiliary footsection, a spring bearing downwardly against the auxiliary foot sectionat a point in front of the pivot thereof, and a spring interposedbetween the presser bars for yieldably retaining the auxiliary footsection against upward bodily movement.

In testimony whereof I afiix my signature.

LOUIS G. BOWMAN.

